#include<iostream>
#include<iomanip>
using namespace std;
int main()
{double a[10000];int n;
 cin>>a[1];
 for(int i=2;;i++)
    {cin>>a[i];
     if(a[i]==999)  break;
     cout<<setiosflags(ios::fixed)<<setprecision(2)<<a[i]-a[i-1]<<endl;
     }
 
 cout<<"End of Output"<<endl;
system("pause");
return 0;
} 
    
 
